The disclosures herein relate generally to heart valves and more particularly to heart valves with a resiliently collapsible retainer.
Presently, the implantation of heart valves requires the surgeon to attach the heart valve to the annulus. One method of attachment is to use sutures. In most cases, the valve is attached using many interrupted sutures or one continuous suture. The use of sutures is time consuming as it requires the surgeon to tie numerous knots.
The technique of using sutures to secure the heart valve to the annulus occurs while the patient is on cardiac-by-pass. It is undesirable to keep a patient on cardiac-bypass for an extended period of time. By eliminating or reducing the need for sutures, the time to secure the valve to the annulus would be reduced. Thus, the time the patient is on cardiac-by-pass may also be reduced.
The space required for implanting prosthetic heart valve devices is limited. This is especially true in less invasive implantation procedures where a minimum incision size is a goal. For these types of implantation procedures, complex, space intensive attachment schemes are undesirable. This is also true in the cases of per- cutaneous insertion of a heart valve using a catheter based system.
U.S. Pat. No. 4,680,031 discloses a "tissue valve type" heart valve prosthesis which has a bio-compatible plastic sewing ring adapted to be surgically implanted into the mitral, aortic or tricuspid annulus of the human heart. The sewing ring has internal square threads and a bio-compatible fabric mesh or cloth that is embedded into the sewing ring so that the cloth can be fully wrapped around the sewing ring covering all of its plastic surfaces except for the internally protruding threads. A bio-compatible plastic stent support ring has externally disposed threads to lock with the threads of the sewing ring in approximately one turn, or less. The stent support ring also embeds a bio-compatible fabric mesh which can be wrapped around the stent support ring to cover all of its plastic surfaces, except for the protruding threads, and to form a cloth pocket wherein a solid stent is mounted.
U.S. Pat. Nos. 5,370,685 and 5,545,214 relate to a valve replacement system together with methods of preparation and use for endovascular replacement of a heart valve in a host. The valve replacement system includes up to five components: (1) a prosthetic valve device, (2) a valve introducer device, (3) an intraluminal procedure device, (4) a procedure device capsule, and (5) a tissue cutter. The system provides for endovascular removal of a malfunctioning valve and subsequent replacement with a permanent prosthetic heart valve.
U.S. Pat. No. 5,411,552 discloses a valve prosthesis for implantation in the body by use of a catheter. The valve includes a stent made from an expandable cylinder-shaped thread structure having several spaced apices. The elastically collapsible valve is mounted on the stent as the commissural points of the valve are secured to the projecting apices. The valve prosthesis can be compressed around the balloon of the balloon catheter and be inserted in a channel, for instance in the aorta. When the valve prosthesis is placed correctly, the balloon is inflated thereby expanding the stent and wedging it against the wall of aorta. The valve prosthesis and the balloon catheter make it possible to insert a cardiac valve prosthesis without a surgical operation that requires opening the thoracic cavity.
U.S. Pat. No. 5,607,465 discloses a valve for use in a blood vessel, internal to the blood vessel itself. The valve has a bent flexible wire mesh with elasticity and plasticity so as to be collapsible and implantable remotely at a desired site. The wire mesh is bent into three turns including two end turns and a central turn, in such a way as to confine a tubular space. The central turn is located at an angle relative to the end turns and mounts a monocusp sail-like valving element. A special catheter is used to collapse the flexible wire mesh to implant it remotely at the desired site and to restore the wire mesh to its original three-dimensional configuration.
U.S. Pat. No. 5,716,370 discloses a technique for replacing a heart valve using minimally invasive methods to reduce the time associated with replacing the valve. This technique includes a sutureless sewing cuff and a fastener delivery tool that holds the cuff against the patient's tissue while delivering two fasteners. The fasteners are delivered two at a time in opposite directions to attach the cuff to the tissue from the inside out. Drawstrings are operated from outside the patient's body and cinch the sewing cuff to the valve body. The cuff is releasably mounted on the tool. The tool stores a plurality of fasteners thereon. Two rows of staggered fasteners are formed whereby fasteners are located continuously throughout the entire circumference of the cuff.
U.S. Pat. No. 5,855,601 discloses an artificial heart valve including a relatively rigid stent member having a first cylindrical shape and a flexible valve disposed in the stent member. The stent member is self-expandable to a second cylindrical shape and collapsible to its first cylindrical shape. The valve comprises a circular portion comprising a plurality of leaflets extending from the periphery of the circular portion towards the center thereof. The leaflets are configured to allow for flow of blood through the valve in one direction only. The diameter of the circular portion is substantially the same as the inside diameter of the stent member when the stent member is in its second cylindrical shape. The valve member is attached to the stent member.
Although attempts have been made to reduce the time and space required for implantation, these attempts have provided only limited success. Accordingly, there is a need for an improved heart valve prosthesis that overcomes the shortcomings of present heart valves.